Telephone substation apparatus



April 23, 194-0 c, WALKER 2,197,844

' TELEPHONE SUBSTATION APPARATUS Filed Jan. 26, 1938 v 2 Sheets-Sheet J FIG. 2 3 a0 30 I6 32 2 2 3/ T 17 I5 27 3/ E Z/ 0 v 4 4 20 2/ 34 ga 35 a 2 W5.

INVENTOR ACIWALKER 8V 04mm M A 7' TORNEV Patented Apr. 23, 1940 UNITED STATES- 2,197,844 TELEPHONE SUBSTATION APPARATUS Albert C. Walker, Short Hills, N. J., assignor'to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application January 26, 1938, Serial No. 186,961

v 1 Claim. This invention relates to telephone substation I apparatus and more particularly to mountings.

for hand telephones.

Telephone substation apparatus usually com- 5 prises a mounting or casing havingtherein vario-us elements of a telephone subset, and a hand telephone, the instrument or instruments of which are connected incircuit with the subset elements by a cord. If proper care is not-taken in the use of the telephone apparatus; this cord may become twisted or kinked.

One general object of this invention, therefore, is to prevent undesired twisting and kinking of hand telephone cords inv telephone substation apparatus. More specifically, oneobject of this invention is to avoid undesired twisting and kinking of such cords in a facile and economic manner and without'the introduction into the substation circuits of contact or circuit controlling members in addition to those normally utilized.

In one illustrative embodiment of thisinvention, a telephone set comprises a desk mounting having generally'the usual elements of substation apparatus therein, a hand telephone, and a cord for electrically connecting the telephonic units of hand telephone in circuit with the elements within the mounting." The mounting is provided with a cradle for'accommodating the hand telephone, line contact members, and a plunger for actuating the contact members in accordance with the placement of the hand telephone upon the cradle or the removal of the hand telephone from the cradle.

In accordance with one feature of this invention, the conductors of the cord are terminated at a swivel element or plug mounted so as to be freely rotatable within the mounting. The plug has a series of spaced conductive sections, each of which is adapted tomake wiping contact with a corresponding one of the line contact members, Means are provided, such as the hookswitch element in the set, actuable in response to the removal of the hand telephone from the cradle, to

allow firm engagement of the line contacts with the conductive sectionsof the plug so that an emcient and low resistance connection is established between the contacts and the conductive sections while the telephone set is in use.

The invention and the foregoing and other features thereof will be understood more clearly and fully from the following detailed description with reference to the accompanying drawings in which:

Fig. 1 is a perspective view of a telephone desk set illustrative .of one embodiment of this invention;

Fig. 2 is a front view, partly in section and partly broken away, of the -mounting of the telephone set shown in Fig. 1, illustrating 'the. association of the telephone cord, plunger, plug and line contacts, in accordance with this invention; a

Fig. 3 is a fragmentary side view, partly in section, along line 3-3 of Fig. 2, further illus- I trating the association of the plunger, plug and line contacts; I V Fig. 4 is a fragmentary plan view along line- 44' of Fig. 2, 'showing 'the relative positions of the linecontacts and the plug, when the hand 15 telephone is removed from the cradle of the mounting; and I 1 r I Fig.5 is a view similar to Fig. 4 illustrating the association of the contacts and the plug when the hand telephone is seated in the cradle of the 20 mounting. Referring now to the drawings, the telephone desk set shown in Fig. 1 comprises a mounting l0 having a plurality of tines l I forming a cradle for receiving a hand telephone l2. The mount- 25 ing Ill may have therein the various elements of substation apparatusynot shown, such as a condenser, induction coil and ringer." The hand telephonev 12 includes a transmitter, not shown, mounted at one end l3 and a receiver, not shown, 30 mounted at the other end M. The transmitter and receiver areelectrically associated with the substation elements through a flexible cord l5 which includes a plurality, for example three, of conductors.

Secured to theinner wall of the upper portion of the mounting, as shown in Fig. 2, is a support; ing member or bracket, for example a metallic stamping, having arms Hi apertured to receive screws ll threaded into the housing, parallel extensions or flanges I8, and an integral supporting lug or flange I9. Afilxecl to the lug or flange l9, as by screws 20, is a bearing block 2|, for example of metal, which carriesa line contact assembly including elongated contact 45 springs 22, having integral soldering terminals 45. The springs 22 are insulated from each other by insulating spacers 23 and insulating washers 33 and, together with the spacers 23, may be aifixed to the block by suitable screws 24. 50

s The extensions or flanges l8 have extending therebetween an axle or shaft 25 on which a rocker member 26 is pivotally supported. The rocker member has parallel arms 21 through which the shaft'or axle 25 extends and is pro- 55 21 of the rocker member, by pins 3|.

A plug member 43 is rotatably fitted in a bore 1 in the bearing block 2! and is provided with three conductive, generally cylindrical sections 34, preferably coated with a low resistance material such as silver, insulated from each other by insulating rings or collars 35. Each of the conductive sections 34 is connected electrically to a corresponding one of the conductors of the cord l5 and is adapted to be engaged by one of the contact springs 22. The plug 43 has a head M engaging one end of the block 2 I. 'One surface of the head 44 bears against the inner wall of the. mounting In so that the plug is held in position. Alternatively, the head M may be omitted and the plug 43 held in position by other means such .as a set screw extending through one wall of the bearing block 2| and having its end projecting into an annular groove in the plug. In such case, the aperture in the housing through which the cord and end of the plug pass preferably is sufiiciently large to allow passage of the plug therethrough, so that the plug may be associated and dissociated readily with the bearing plugand the contact springs. If desired, the contact springs may have thereon relatively soft, low resistance contact bars 36 adapted to make wiping engagement with the conductive sections 34 of the plug.

When the hand telephone is in the cradle, the plungers 30 are depressed and actuate the rocker member 25 so that the finger or lip 28 bears against the extension 29 and moves the contact springs 22 out of engagement with the plug sections 34 as indicated in Fig.5. Hence, the telephone set isdisconnected from the telephone line.

When the hand telephone is removed from the cradle, the springs 22, acting in concert through the extension 29, cause rotation of the rocker member through an arc limited by the stop 32.

prevented. Such rotation of the plug in unison with the cord may occur not only when the hand. telephone is in the cradle but also when the hand.

telephone has been removed from the cradle, inasmuch as in the latter case the springs 22 need not bear against the sections 34 with sufficient force to prevent rotation of the plug. Of course,

the contact springs may be so designed that the pressures normally specified between the springs and the plug for satisfactory'operation are obtaineo'L.

. talking and receiving circuit, occasioned by additional contacts in devices suggested heretofore, is prevented.

It may be pointed out also that because of the,

continual wiping action between the springs 22 and the sections 34 of the plug, clean, low resistance and efficient connections obtain.

It will be appreciated, moreover, that this in vention provides a relatively simple and inexpensive contact spring and plug arrangement which may be incorporated readily in standard telephone sets. a

Although a specific embodiment of the invention has been shown and described, it will be understood, of course, that this embodiment is but illustrative and thatvarious modifications may be made therein without departingfrom the scope and spirit of this invention as defined in the appended claim.

What is claimed is: l

A telephone set comprising a' housing having a cradle portion for accommodating a hand telephone, a reciprocable plunger extending through said housing and projectinginto said cradle, a bracket member secured to an inner wall of said housing and having a pair of spaced arms and a flange, a rocker member supported by said arms and connected to said plunger, said rocker member having a projecting finger, an elongated bearing block secured to said flange and having a bore therein, a plurality of elongated contact springs fixed at one end on said bearing block and insulatingly coupled adjacent the other end, one of i said springs engaging said finger, a plug extend ing through said bore and freely rotatable therein, said plug having a plurality of collar portions insulated from one another and engageable by said springs, and a multiconductor cord connected to said collars and to the hand telephone.

ALBERT CQWALKER. 

